Agricultural implement hydraulic rephasing unit and method

ABSTRACT

An agricultural system includes a frame, a hydraulic system, a controller and a plurality of sensors. The hydraulic system is coupled to the frame and has a plurality of hydraulic actuators fluidically coupled in a series arrangement. The controller is in control of the hydraulic system. The plurality of sensors have at least one sensor coupled to each of the plurality of hydraulic actuators. The sensors are in communication with the controller, and the controller is configured to receive at least one signal from the sensors that indicate a need to rephase the hydraulic actuators, to estimate an amount of time needed to rephase the hydraulic actuators, and to alter a function of the agricultural system to allow for the hydraulic actuators to be rephased in the time needed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to agricultural implements, and, moreparticularly, to a system that rephases series hydraulic cylinders of anagricultural implement.

2. Description of the Related Art

Farmers utilize a wide variety of tillage implements to prepare soil forplanting. Some such implements include two or more sections coupledtogether to perform multiple functions as they are pulled through fieldsby a tractor. For example, a field cultivator is capable ofsimultaneously tilling soil and leveling the tilled soil in preparationfor planting. A field cultivator has a frame that carries a number ofcultivator shanks with shovels at their lower ends for tilling the soil.The field cultivator converts compacted soil into a level seedbed with aconsistent depth for providing excellent conditions for planting of acrop. Grass or residual crop material disposed on top of the soil isalso worked into the seedbed so that it does not interfere with aseeding implement subsequently passing through the seedbed.

Tillage equipment prepares the soil by way of mechanical agitation ofvarious types, such as digging, stirring, and overturning. Examples ofwhich include ploughing (overturning with moldboards or chiseling withchisel shanks), rototilling, rolling with cultipackers or other rollers,harrowing, and cultivating with cultivator shanks.

The lifting of the tillage elements from the field, and the folding ofthe sections are typically actuated with a hydraulic system. Hydraulicsystems that utilize a pressurized fluid through a series of pistons isgenerally known. Typically, it is important to have the pistons of aseries arrangement synchronized with respect to one another.Synchronization of the system is accomplished by having the pistonsreach the top and the bottom of their respective strokes at the sametime. This is especially desirable when raising and lowering componentsof a piece of equipment.

During operation of the hydraulic system the pistons may get out of syncdue to imperfections in the pistons/cylinders and due to wear of variousparts on the pistons and cylinders. Most commonly, seals can wear andbegin to degrade over time, thereby allowing the hydraulic fluid withinthe system to bypass the pistons and/or leak out of the system. When thefluid is removed from the system or becomes unbalanced, by leaking orotherwise, a decrease in pressure within the system occurs causing thepistons to travel by differing amounts or by a varying speed, therebycausing the pistons to begin and end their strokes at different times.During the raising and lowering of the components of the equipment, thevariation in piston movement will not allow the components to movesmoothly and safely. To remedy this problem, the pistons need to beresynced. The process of resyncing the pistons in the series hydraulicsystem is commonly known as rephasing.

The typical way to rephase hydraulic systems require an operator tonotice the need to rephase, and the operator then causes the system tofully extend the hydraulic actuators to allow the built in fluidchannels to adjust the fluid present between the pistons.

A problem with these systems is that the operation requires the operatorto note the need and to execute the sequence.

What is needed in the art is a system that will detect the need forrephrasing and select a time that is energy efficient and not when theimplement is performing its primary duty.

SUMMARY OF THE INVENTION

The present invention provides a rephasing solution for seriallyarranged actuators.

The invention in one form is directed to an agricultural implementincluding a frame, a hydraulic system and a controller. The hydraulicsystem is coupled to the frame. The hydraulic system has a plurality ofhydraulic actuators fluidically coupled in a series arrangement. Theimplement has a transport mode, a headland mode and a ground engagingmode. The controller is in control of the hydraulic system, and executesthe steps of detecting that the implement is in the transport mode orthe headland mode; and operating the hydraulic system to rephase thehydraulic actuators dependent upon the detection of the transport modeor the headland mode in the detecting step, and an estimated amount oftime needed to rephase the hydraulic actuators; and altering a functionof the agricultural system to allow for the hydraulic actuators to berephased in the time needed.

The invention in another form is directed to an agricultural implementincluding a frame, a hydraulic system, a controller and a plurality ofsensors. The hydraulic system is coupled to the frame and has aplurality of hydraulic actuators fluidically coupled in a seriesarrangement. The controller is in control of the hydraulic system. Theplurality of sensors have at least one sensor coupled to each of theplurality of hydraulic actuators. The sensors are in communication withthe controller, with the controller executing the steps of receiving atleast one signal from the sensors indicating a need to rephase thehydraulic actuators; estimating an amount of time needed to rephase thehydraulic actuators; and altering a function of the agricultural systemto allow for the hydraulic actuators to be rephased in the time needed.

An advantage of the present invention is that a less skilled operatorcan be used to operate the agricultural implement.

Another advantage is that the present invention detects when rephasingshould be undertaken.

Yet a further advantage is that the present invention delays therephasing until an opportune time, such as during a headlands turn.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a top schematical view of an embodiment of an agriculturaltillage implement of the present invention, in the form of a fieldcultivator, in an unfolded position being pulled by a tractor;

FIG. 2 is a rear view of the agricultural implement shown in FIG. 1;

FIG. 3 is a schematical representation of a series hydraulic system inuse on the implement of FIGS. 1 and 2;

FIG. 4 is a schematical representation of a travel path of the implementof FIGS. 1 and 2;

FIG. 5 is a schematical block diagram of a control system that operatesthe hydraulic system of FIG. 3 on the agricultural implement of FIGS. 1and 2; and

FIG. 6 is a flowchart depicting a method used by the control system ofFIG. 5.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplification set out hereinillustrates embodiment of the invention, in one form, and suchexemplification is not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIGS. 1 and 2,there is shown an embodiment of a tillage implement of the presentinvention. In the illustrated embodiment, the tillage implement is inthe form of a field cultivator 10 for tilling and finishing soil priorto seeding. Field cultivator 10 is being pulled by a tractor T in atravel direction D.

Field cultivator 10 is configured as a multi-section field cultivator,and includes a center frame section 12, also referred herein as a mainsection 12, and a plurality of wing sections 14 and 16. In theillustrated embodiment, field cultivator 10 has a dual-foldconfiguration with two left wing sections designated 14A and 16A, andtwo right wing sections designated 14B and 16B. Wing sections 14A and14B are each inner wing sections, wing sections 16A and 16B are eachouter wing sections. Throughout this application when the suffixes A andB are used they refer to a side of implement 10, and the use of thereference number absent the suffix is meant to refer to both the A and Bsections.

Center frame section 12 is the center section that is directly towed bya traction unit, such as an agricultural tractor T. A pull hitch 18extends forward from center frame section 12, and is coupled with thetraction unit T in a known manner.

Sections 12-16 typically have cultivator shanks 20 coupled thereto forthe cultivating or tilling of the ground. Each shank 20 may have atilling portion; such as shovels at their lower ends for tilling thesoil. Wheel assemblies 22 are coupled to main section 12 and are usedfor raising and lowering main section 12 with hydraulic lift cylindersor actuators 28A and 28B, during the tilling operation, and is usedduring the transport mode. In a similar manner actuators 30A and 30B arerespectively coupled to wheel assemblies 24A and 24B, and actuators 32Aand 32B are coupled to wheel assemblies 26A and 26B.

During use, it is periodically necessary to move implement 10 from aground engaging mode where shanks 20 are lowered and make contact withthe soil to an elevated mode (as seen in FIG. 2) with shanks 20 raisedfrom the soil, which can also be referred to as a headland mode. Thetransition to headland mode is accomplished by actuating actuators 28,30 and 32 thus extending wheel assemblies 22, 24 and 26 to thereby raisethe frames of implement 10 and shanks 20 thereby. While in a headlandmode, implement 10 is usually turned to go in an opposite direction tocontinue a field operation. Once the turn in completed then actuators28, 30 and 32 are retracted to a controlled position to control thedepth that shanks 20 engage the soil in the ground engaging mode.

Implement 10 can also transition from an unfolded orientation, as shownin FIG. 2, to a transport orientation which is a folded position. Tofold implement 10, first, each outer wing section 16A and 16B is foldedlaterally inward and over a respective inner wing section 14A and 14B.With the outer wing sections 16A and 16B in the folded state, each innerwing section 14A and 14B is then folded.

Whether or not implement 10 is a folding implement, actuators 28, 30 and32 are used to elevate implement 10 and to regulate the depth thatshanks 20 engage the soil.

Now, additionally referring to FIG. 3, there is shown actuators 28, 30,32, and N that schematically represent a serial connected hydraulicsystem 50. Relative to implement 10, actuators 28-N can represent one ormore serial systems that are used to extend wheel assemblies 22, 24 and26 or actuators 28-N can represent the movement of some other part ofimplement 10, where the use of serially linked actuators is desirable.

Now, additionally referring to FIG. 4, there is schematically shown afield 52 having an implement travel path 54 and headland boundaries 56and 58, which respectively define headland areas 60 and 62 to the leftand right of boundaries 56 and 58. As implement 10 travels in directionD along path 54 implement 10 will cross boundary 56 and implement 10will transition to the headland mode with actuators 28-N being actuated.As implement 10 is turned to go in an opposite direction, implement 10transitions from the headland mode to the ground engaging mode asimplement 10 leaves headland area 60. In a like manner as implement 10reaches headland area 62 a similar set of actions take place asimplement 10 again changes direction.

Referring now to FIGS. 5 and 6, there is shown a control system 64having a controller 66, and a valve 68. Controller 66 is incommunication with a position system 70, a speed control 72, an engine74 of tractor T, and a user interface 76 located in a cab of tractor T.Sensors S1 though SN are coupled to actuators or cylinders 28 through N.Sensor S1-SN can be positional sensors that sense the actual positon ofpistons P1-PN and can determine the relative differences in thepositions. Controller 66 executes method 100 and receives positionalinformation or signals representative of the positions of pistons P1-PNat step 102. At step 104, if the relative positions of pistons P1-PNdiffer above a predetermined value X, which may be user selectable, thenmethod 100 proceeds to step 106. A flag may be set in a memory locationunder the control of controller 66, which indicates that a rephasing ofactuators 28-N should be undertaken and a message to that effect is sentto user interface 76. The initiation of the rephasing is delayed at step108 until a selected event occurs at step 108. The selected event can bethe operator indicating, on user interface 76, that the rephasing shouldtake place. Another selected event can be the initiation of a transitionto a headland mode of implement 10. Yet another selected event can bethe location by position system 70 (which may be a GPS system) that aheadland area 60 or 62 has been entered. The occurrence of the selectedevent at step 108 causes method 100 to advance to step 110, andactuators 28-N undergo a rephasing operation with actuators 28-N beingfully extended. When actuators 28-N are fully extended the hydraulicfluid is allowed to pass, to some extent, past pistons P1-PN so that thefluid is proportioned to reflect the fully extended positions of pistonsP1-PN. The extended position may be held for a predetermined time, suchas approximately 5 seconds.

Sensors S1-SN can be proximity sensors rather than sensors that measurethe actual positions of pistons P1-PN throughout their entire travel.The triggering of the proximity sensors then serves to give relativeposition information about pistons P1-PN to controller 66, and method100 can be executed with that information.

In one embodiment of the invention agricultural implement 10 includes aframe F, a hydraulic system 78, a controller 66 and a plurality ofsensors S1-SN. The hydraulic system 78 is coupled to the frame F and hasa plurality of hydraulic actuators 28-N fluidically coupled in a seriesarrangement. The controller 66 is in control of the hydraulic system 78.The plurality of sensors S1-SN have at least one sensor coupled to eachof the plurality of hydraulic actuators 28-N. The sensors S1-SN are incommunication with the controller 66, with the controller executing thesteps of receiving at least one signal 102 from the sensors S1-SNindicating a need to rephase the hydraulic actuators; and operating thehydraulic system 78 to rephase 110 the hydraulic actuators 28-Ndependent upon the signal.

In another embodiment of the invention the agricultural implement 10includes a frame F, a hydraulic system 78 and a controller 66. Thehydraulic system 78 is coupled to the frame F. The hydraulic system 78has a plurality of hydraulic actuators 28-N fluidically coupled in aseries arrangement. The implement 10 has a transport mode, a headlandmode and a ground engaging mode. The controller 66 is in control of thehydraulic system 78, and executes the steps of detecting 108 that theimplement 10 is in the transport mode or the headland mode; andoperating 110 the hydraulic system 78 to rephase the hydraulic actuatorsdependent upon the detection of the transport mode or the headland modein the detecting step 108.

Series hydraulic systems, due to the leakage of hydraulic fluid from onecylinder to another, cause the cylinders to be in different positions,commonly called “out of phase”. From time to time, the operator of thehydraulic system must extend the cylinders and hold the extendedposition allowing the bypass groves of the pistons or cylinders to“rephase” the cylinders. Sensors S1-SN may be in the form of positiondepth sensors associated with each of the cylinders or relative to frameF, which can detect an out of phase condition and thus the need forrephasing.

Position sensors S1-SN, located at each cylinder 28-N, indicates whencylinders 28-N are out of phase and signals to user interface 76 in thecab, that implement 10 is out of phase. The operator can stop and takecorrective action, in the form of rephasing, or this can be doneautomatically. The present invention also provides for the rephasing towait (see step 108) and automatically be done at headland turns inheadland areas 60 or 62. Once the system 64 knows it needs to rephase,and the operator lifts implement 10 for the headland turn, thencontroller takes the initiative to rephase actuators 28-N.

If rephasing is not completed by the end of headland turn (when theoperator moves to lower implement 10 back into the ground in the groundengaging mode) the tractor T will stop, thus halting the primary task,and let the phasing operation complete. Once complete, tractor Tautomatically (or from a resume signal from the operator) lowersimplement 10 and continues forward with the primary task of theagricultural operation, such as engaging and moving soil. With GPS fieldmaps, the lifting and lowering can be automatic so that as implement 10reaches headland areas 60 or 62, the rephasing, if needed, is carriedout during the turn operation.

Indications of a need to “rephase” actuators 28-N is displayed on userinterface 76 and the automatic rephase of cylinders 29-N takes placeupon the lifting of implement 10 (normally at the headland 60 or 62). Atractor stopping feature is contemplated so that if the rephase is notcompleted and the tractor is prevented from moving, there is a manualrestart button to continue tractor operations. Alternatively, this canbe automatic if so desired.

It is also contemplated to use a limiting position sensor on just theoutside cylinders N, as they normally show the most movement ofcylinders due to leakage.

It is further contemplated that if that rather than a stop/startfeature, controller 66 could use the hydraulic scrapper controls ontractor T, for auto correction.

When the cylinders 28-N should be rephased, the system automaticallyrephases (moves to transport position) when the operator indicates moveto the headland position. If tractor T does not rephase in time tocomplete the headland turn, such as when the operator hits the depthresume button, the tractor stops, until rephasing is complete. Then theoperator hits a tractor resume button on operator interface 76 to gettractor T moving again or tractor T can automatically resume on its own.The controls utilize ISOBusc3 tractor controls (stop/start). As analternative, controller 66 of tractor T has knowledge of how long ittakes to complete a headland turn (controller 66 records an average timebetween button hits between operating depth and headland), and slowstractor T down to match that rephasing time. Therefore, no need to stopand start tractor T, wherein the controls utilize ISOBusc3 tractorcontrols (speed control 72 and or engine 74) to accomplish the speedalteration. In one embodiment of the present invention, the amount oftime needed to rephase cylinders 28-N is made by controller 66. Thespeed function 72 of tractor T is under the control of controller 66when in the headland area of the field, so that the speed of tractor Ton the ground is made to approximate the time needed to rephasecylinders 28-N as the turn in the headland is undertaken and completed.Once the rephase is completed implement 10 is returned to the operatingmode and the speed of tractor T is resumed at the operating speed.

The use of the word “implement” herein is used to mean an agriculturalsystem in the form of a device pulled by a tractor T, or to mean aself-propelled implement, or to mean the combination of a tractor T andan implement 10. The operator of the agricultural system can enter, onuser interface 76, an amount of variation, which may be thought of as anadjustable tolerance range, that is allowed in the actual positions ofcylinders 28-N before step 104 indicates that the position difference issufficient to require a rephase at step 106.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

What is claimed is:
 1. An agricultural system, comprising: an implementconfigured to be connected to and moved a tractor, the implementincluding a frame connected to the tractor and having at one shank whichengages the ground when the implement is in a ground engaging mode, theat least one shank lifted above the ground when the implement is in aheadland mode; a hydraulic system coupled to the frame, the hydraulicsystem having a plurality of hydraulic actuators fluidically coupled ina series arrangement; a controller configured to control the hydraulicsystem and in communication with the tractor; and a plurality of sensorswith at least one sensor coupled to each of the plurality of hydraulicactuators, the sensors in communication with the controller, wherein thecontroller is configured to receive at least one signal from the sensorsthat indicates a need to rephase the hydraulic actuators, wherein thecontroller rephrases the hydraulic actuators during a predeterminedevent, including the headland mode, and the controller estimates anamount of time needed to rephase the hydraulic actuators during thepredetermined event, wherein the controller controls the speed of therephasing of the hydraulic actuators as well as the speed of thetractor, wherein the controller is configured to control the amount oftime needed for the rephrase such that the rephrase of the hydraulicactuators is started and completed during the predetermined event byaltering the speed of the tractor and the implement to allow for thehydraulic actuators to be rephased during the time of the predeterminedevent, and wherein the tractor and the implement continue to move duringthe rephrase of the hydraulic actuators when the predetermined event isthe headland mode.
 2. The agricultural system of claim 1, wherein thecontroller automatically rephrases the hydraulic actuators during apredetermined event.
 3. The agricultural system of claim 2, wherein thepredetermined event is an operator initiated action.
 4. The agriculturalsystem of claim 3, wherein the controller informs an operator that arephase action is needed and the operator initiates a confirmationsignal to the controller.
 5. The agricultural system of claim 1, whereinthe controller delays a rephase action until the agricultural system isin a predetermined location.
 6. The agricultural system of claim 5,further comprising a position determining system, the predeterminedlocation of the agricultural system being determined by the positiondetermining system.
 7. The agricultural system of claim 5, wherein thepredetermined location of the agricultural system is a headland area ofa field.
 8. The agricultural system of claim 7, wherein the controlleralters the hydraulic system to rephase the hydraulic actuators when thesystem is in the headland area, the duration of the turn being selectedby the controller to proximate the estimated amount of time needed. 9.The agricultural system of claim 7, wherein the hydraulic actuators arepositioned in a fully extended position for a predetermined amount oftime when the hydraulic system is rephased.
 10. The agricultural systemof claim 1, wherein the at least one shank is lifted when thepredetermined event is the headland mode.
 11. The agricultural system ofclaim 1, wherein the controller stops the agricultural system frommoving in the field until the controller has completed an alteration ofthe hydraulic system to rephase the hydraulic actuators when thepredetermined event is not the headland mode.
 12. The agriculturalsystem of claim 1, wherein when the signal is received by thecontroller, the sensors provide a first signal to the controller thatindicates if the hydraulic actuators are out of phase more than anoperator selected amount before providing a second signal to thecontroller that indicates that the hydraulic actuators need to berephased.